Emergence of liquid following laser melting of gold thin films

X-ray structural science is undergoing a revolution driven by the emergence of X-ray Free-electron Laser (XFEL) facilities. The structures of crystalline solids can now be studied on the picosecond time scale relevant to phonons, atomic vibrations which travel at acoustic velocities. In the work presented here, X-ray diffuse scattering is employed to characterize the time dependence of the liquid phase emerging from femtosecond laser-induced melting of polycrystalline gold thin films using an XFEL. In a previous analysis of Bragg peak profiles, we showed the supersonic disappearance of the solid phase and presented a model of pumped hot electrons carrying energy from the gold surface to scatter at internal grain boundaries. This generates melt fronts propagating relatively slowly into the crystal grains. By conversion of diffuse scattering to a partial X-ray pair distribution function, we demonstrate that it has the characteristic shape obtained by Fourier transformation of the measured F(Q). The diffuse signal fraction increases with a characteristic rise-time of 13 ps, roughly independent of the incident pump fluence and consequent final liquid fraction. This suggests the role of further melt-front nucleation processes beyond grain boundaries

Development and Verification of Time-Series Deep Learning for Drug-Induced Liver Injury Detection in Patients Taking Angiotensin II Receptor Blockers: A Multicenter Distributed Research Network Approach

Objectives The objective of this study was to develop and validate a multicenter-based, multi-model, time-series deep learning model for predicting drug-induced liver injury (DILI) in patients taking angiotensin receptor blockers (ARBs). The study leveraged a national-level multicenter approach, utilizing electronic health records (EHRs) from six hospitals in Korea. Methods A retrospective cohort analysis was conducted using EHRs from six hospitals in Korea, comprising a total of 10,852 patients whose data were converted to the Common Data Model. The study assessed the incidence rate of DILI among patients taking ARBs and compared it to a control group. Temporal patterns of important variables were analyzed using an interpretable time-series model. Results The overall incidence rate of DILI among patients taking ARBs was found to be 1.09%. The incidence rates varied for each specific ARB drug and institution, with valsartan having the highest rate (1.24%) and olmesartan having the lowest rate (0.83%). The DILI prediction models showed varying performance, measured by the average area under the receiver operating characteristic curve, with telmisartan (0.93), losartan (0.92), and irbesartan (0.90) exhibiting higher classification performance. The aggregated attention scores from the models highlighted the importance of variables such as hematocrit, albumin, prothrombin time, and lymphocytes in predicting DILI. Conclusions Implementing a multicenter-based time-series classification model provided evidence that could be valuable to clinicians regarding temporal patterns associated with DILI in ARB users. This information supports informed decisions regarding appropriate drug use and treatment strategies

Fabrication of Stacked MoS 2 Bilayer with Weak Interlayer Coupling by Reduced Graphene Oxide Spacer

© 2019, The Author(s). We fabricated the stacked bilayer molybdenum disulfide (MoS 2 ) by using reduced graphene oxide (rGO) as a spacer for increasing the optoelectronic properties of MoS 2 . The rGO can decrease the interlayer coupling between the stacked bilayer MoS 2 and retain the direct band gap property of MoS 2 . We observed a twofold enhancement of the photoluminescence intensity of the stacked MoS 2 bilayer. In the Raman scattering, we observed that the E 1 2g and A 1g modes of the stacked bilayer MoS 2 with rGO were further shifted compared to monolayer MoS 2 , which is due to the van der Waals (vdW) interaction and the strain effect between the MoS 2 and rGO layers. The findings of this study will expand the applicability of monolayer MoS 2 for high-performance optoelectronic devices by enhancing the optical properties using a vdW space

SCAPS-1D Simulation for Device Optimization to Improve Efficiency in Lead-Free CsSnI₃ Perovskite Solar Cells

In this study, a novel systematic analysis was conducted to explore the impact of various parameters, including acceptor density (NA), individual layer thickness, defect density, interface defect density, and the metal electrode work function, on efficiency within the FTO/ZnO/CsSnI3/NiOx/Au perovskite solar cell structure through the SCAPS-1D (Solar Cell Capacitance Simulator in 1 Dimension) simulation. ZnO served as the electron transport layer (ETL), CsSnI3 as the perovskite absorption layer (PAL), and NiOx as the hole transport layer (HTL), all contributing to the optimization of device performance. To achieve the optimal power conversion efficiency (PCE), we determined the ideal PAL acceptor density (NA) to be 2 × 1019 cm−3 and the optimal thicknesses to be 20 nm for the ETL (ZnO), 700 nm for the PAL (CsSnI3), and 10 nm for the HTL (NiOx), with the metal electrode remaining as Au. As a result of the optimization process, efficiency increased from 11.89% to 23.84%. These results are expected to contribute to the performance enhancement of eco-friendly, lead-free inorganic hybrid solar cells with Sn-based perovskite as the PAL

Structural basis of DNA binding by the NAC transcription factor ORE1, a master regulator of plant senescence

Plants use sophisticated mechanisms of gene expression to control senescence in response to environmental stress or aging. ORE1 (Arabidopsis thaliana NAC092) is a master regulator of senescence that belongs to the plant-specific NAC transcription factor protein family. ORE1 has been reported to bind to multiple DNA targets to orchestrate leaf senescence, yet the mechanistic basis for recognition of the cognate gene sequence remains unclear. Here, we report the crystal structure of the ORE1–NAC domain alone and its DNA-binding form. The structure of DNA-bound ORE1–NAC revealed the molecular basis for nucleobase recognition and phosphate backbone interactions. We show that local versatility in the DNA-binding site, in combination with domain flexibility of the ORE–NAC homodimer, is crucial for the maintenance of binding to intrinsically flexible DNA. Our results provide a platform for understanding other plant-specific NAC protein–DNA interactions as well as insight into the structural basis of NAC regulators in plants of agronomic and scientific importance. © 2022 The Author(s)11Nsciescopu

New dithienophosphole-based donor–acceptor alternating copolymers: Synthesis and structure property relationships in OFET

Two donor acceptor conjugated copolymers comprised of a novel dithienophosphole (DTP) as the acceptor unit and bithiophene (BT) or decylthiophenebenzodithiophene (DTBDT) as the donor unit were synthesized and characterized to elucidate the relationship between donor acceptor (D-A) architecture and organic field-effect transistors (OFETs) performance. These characteristics of D-A copolymers were affected by the structural suitability of donor and acceptor units. Poly(DTP-BT) had an ordered structure that facilitated charge carrier transfer. The crystallinity of poly(DTP-BT) increased as annealing temperature (T-ann) increased. In contrast, poly(DTP-DTBDT) was amorphous regardless of Tann due to the long alkyl chains of the DTBDT units. OFET devices made with poly(DTP-BT) and annealed at 200 degrees C exhibit a highly crystalline morphology and a relatively high field-effect mobility (4.9 x 10(-3) cm(2)/(V.s)).115sciescopu